Layer by layer deposition technique in combination with selective metal-ligand coordination has been a powerful tool for generation of complex, self-driven, supramolecular surface confined architectures consisting of functional superlattices. These molecular assemblies, owing to their diverse intrinsic properties, span a wide variety of potential applications ranging from molecular electronics, display and sensor technologies, to solar cells and data storage. It has been reported that the complex properties of these assemblies could be fine-tuned by controlling their growth and mode of deposition. This, in turn, depends on the coordination geometry and molecular structure of the components. Hence, careful and rational design of the backbone structure and geometry could provide a simple, but challenging alternative for achieving control over the properties of multicomponent layer by layer assemblies.
One of the most intriguing properties of selected redox active metal-organic materials—electrochromism—arises from their ability to exhibit valance electron transitions (MLCT, intraligand excitation or intravalance charge transfer) upon electrochemical oxidation or reduction. Electrochromic materials are of profound significance as promising candidates for use in smart windows (electrochromic windows), smart mirrors, display devices (electrochromic paper, goggles, helmet visors), etc. By definition, an electrochromic material is one which, by the application of a potential difference, can alter its optical properties upon reversible redox transformation, with distinguishable absorption/reflection spectra in its oxidized and reduced states. CPNFs constructed from such electrochromic materials of metal-organic nature exemplifies the combined advantages of organic and inorganic thin films. These advantages include long range processibility, transmittance modulation, high coloration efficiency, low switching time, open circuit memory effect and high stability.
International Publication No. WO 2006/085319 discloses a device having reversible and optically readable properties, the device comprising a substrate having an electrically conductive surface and carrying a redox-active layered structure, configured to have at least one predetermined electronic property including at least one of electrodensity and oxidation state, said at least one electronic property being changeable by subjecting the layer structure to an electric field, wherein the electronic properties of the layered structure define an optical characteristic of the structure thereby determining an optical response of the structure to certain incident light, the device enabling to effect a change in said electronic property that results in a detectable change in the optical response of the layered structure. International Publication No. WO 2009/095924 discloses such a device comprising, as a redox-active layered structure, a charged tris-bipyridyl Os2+, Fe2+ or Ru2+ complex, for the optical detection, quantification and detoxification of Cr6+ by reversible metal-substrate electron transfer.
International Publication No. WO 2011/141913 discloses a solid-state, multi-valued, molecular random access memory device, comprising an electrically, optically and/or magnetically addressable unit, a memory reader, and a memory writer. The addressable unit comprises a conductive substrate; one or more layers of electrochromic, magnetic, redox-active, and/or photochromic materials deposited on the conductive substrate; and a conductive top layer deposited on top the one or more layers. The memory writer applies a plurality of predetermined values of potential biases or optical signals or magnetic fields to the unit, wherein each predetermined value applied results in a uniquely distinguishable optical, magnetic and/or electrical state of the unit, thus corresponding to a unique logical value. The memory reader reads the optical, magnetic and/or electrical state of the unit.
International Publication No. WO 2014/009952 discloses a logic circuit for performing a logic operation comprising a plurality of predetermined solid-state molecular chips, each molecular chip having multiple states obtained after application of a corresponding input. After applying predetermined inputs on the molecular chips, reading the states of the molecular chips produces a logical output according to the logic operation.
International Publication No. WO 2014/061018 discloses a device having an electrically conductive surface and carrying a molecular assembly, preferably composed of two or more redox-active based molecular components arranged in a specific order or sequence, such that the sequence of the components and their thickness dictate the assembly properties and consequently the uses of the device. Such a device can be used in fabrication of a multistate memory, electrochromic window, smart window, electrochromic display, binary memory, solar cell, molecular diode, charge storage device, capacitor, or transistor.
The aforesaid patent publications are herewith incorporated by reference in their entirety as if fully disclosed herein.